There are various woodworking methods employed in the construction of buildings with wooden members. As shown in FIGS. 8 to 10, a so called "metal fit" joint is illustrated using a metal plate connector A having a pair of metal protrusions 203 and 204. The "metal fit" joint is used for connecting a horizontal wooden member to a vertical wooden member having a special slot to be discussed below. The metal protrusions 203 and 204 are provided with end plates 205 and 206, respectively. The end plates 205 and 206 can be attached, for example, by welding. The metal plate 200 is provided with a hole 202 and a U-shaped slot 201 for connecting the metal plate 200 to the horizontal wooden member with fasteners.
The method of forming the joint is illustrated in FIGS. 9 and 10. The horizontal member or beam 310 is connected to the metal plate connector A by bolts 313 and 314. The beam 310 also has an end slit at its end (not shown) for accommodating the metal plate connector A.
The metal protrusions 203 and 204 have welded end plates 205 and 206, respectively, which are received in joints 301 and 302 of the wooden member or column 300, as shown in FIG. 10.
Once the metal protrusions 203 and 204 are fully fitted into the joints 301 and 302, the metal plate connector A is hit downwardly with an appropriate tool to set the metal plate connector A firmly in the column 300, as shown in FIG. 10.
As shown in FIG. 10, a pin 313 having a D-shaped cross section is inserted through the beam 310 and metal plate connector A. The beam 310 is then moved in a direction until the end grain of the beam 310 meets the column 300 completely.
The beam 310 is then pushed down from its upper side until the pin 313 registers with the bottom of slot 201, as shown in FIG. 10. The beam 310 is further forced downwardly with appropriate pressure, and the pin 314 is inserted through the beam 310 and metal plate connector A. Nuts are threaded onto and tightened on the pins 313 and 314.
In order to use the metal plate connector A to connect the beam 310 to the column 300, it is necessary to provide joints 301 and 302 in the column 300.
The joints 301 and 302 are made by first drilling holes 300a in the column 300. Top plan view of the holes 300a are shown in FIG. 11. Here, the pair of holes 300a are drilled in the column 300 with a standard drill bit. Secondly, smaller width slots 300b are made extending from the holes 300a with a rotary cutting bit. Thirdly, larger width slots 300c are made extending from the holes 300a with a different rotary bit.
Thus, the holes 300a having cylinder shaped cross sections, slots 300b have rectangular shaped cross sections, and slots 300c have rectangular shaped cross sections. The slots 300c are positioned just beneath the slots 300b.
In order to make joints 301 and 302, three (3) different types of drills or cutting tools are required. Specifically, the tools required are as follows:
1. a first cutting bit for making holes 300a having a cylindrical shaped cross section and oriented substantially perpendicular to the surface of the wooden column; PA1 2. a second cutting bit for making the small width slots 300b extending from the holes 300a. The smaller width slots 300b are cut to have a first predetermined depth extending downwardly from the surface of the wooden column; and PA1 3. a third cutting bit for making the larger width slots 300c extending from the holes 300a. The larger width slots 300c are cut to have a second predetermined depth extending from the bottom of the smaller width groove deeper into the wooden column. PA1 1. set the pair of drilling/cutting tools of the machine at a predetermined distance dictated by the spacing between the metal protrusions of the metal plate connector to be used; PA1 2. set the base to align the wooden member relative to the pair of drilling/cutting bits (e.g. the wooden member is aligned lengthwise (FIG. 11) or sideways (FIG. 12) PA1 3. start the machine causing the drilling/cutting tool to rotate the drilling/cutting bit, and move the drilling/cutting bit in contact with the wooden member to bore a cylindrical shaped hole (the drilling/cutting tool is set to drill a predetermined depth hole prior to this operation. PA1 4. after forming the holes, the drilling/cutting tool is moved along the length of the wooden member to simultaneously cut the smaller width groove and the larger width groove. This completes the drilling of the joints.
As explained above, such drilling method requires three (3) different tools including a twist drill bit, a flat drill bit and a rotary side cutting bit. To make highly accurate holes and slots, it is required that the bits be change for each cut. This requires exact setting of the drill at appropriate marks as well as setting the exact moving distance and direction of the drill. Thus, the conventional method takes a significant amount of time, and is troublesome due to the requirement of exchanging the bits, and time and trouble associated with setting the drill for accuracy with each different bit.